Genome may be future step for virus writers

Gene genie

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Advances in genetic circuits may mean that virologists will have to look at the mechanics of Internet worms for a model of future threats.

Recent technological advances in so-called genetic circuits have brought closer a world where cells and viruses could be modified to more effectively serve humans, but also have raised concerns that programmable life could lead to a host of tailored threats similar to Internet worms.

In a paper in the 28 April issue of Nature, researchers at Princeton University and the California Institute of Technology announced that they had successfully modified the genetic code of a group of cells, programming the cluster to form different patterns based on the chemicals present in their environment. The results, while basic, highlight significant advances in the modification of biological organisms, said Ron Weiss, Associate Professor of Electrical Engineering at Princeton and a co-author of the paper.

"Developments are going to move fairly quickly," Weiss said. "At some point, we will have very good control over biological organisms, maybe to the level that we are with computers today."

While computer scientists have modeled virtual life in simulation, the new programming techniques could mean that simple, tailored-made life could be a few decades away. The current stage of development is analogous to the state of transistor research in the late 1940s and early 1950s, Weiss said. He and his colleagues have already created the biological equivalent of many logical components common in the digital world, such as AND, NAND, and NOR gates.

Significant strides are being made in related fields as well. In July 2002, researchers at State University of New York at Stony Brook announced they had recreated the polio virus using a DNA mapping downloaded from a genome database accessible on the Internet. And last December, a Harvard Medical School doctor teamed with a University of Houston researcher to create a DNA molecular chain of 14,500 chemical units, about twice that of the polio virus, effectively increasing the biological equivalent of program length.

The goal is the beneficial modification of organisms to serve specific functions, Weiss said. Plants could be modified to act as detectors of dangerous chemicals and pathogens, and specialised cells could be created to deliver non-differentiated stem cells to help regenerate tissue.

He acknowledges, however, that the technology could be abused. "With any powerful technology we have to be very careful of what we do," he said.

Yet, if the proliferation of tailored-made Internet threats is any measure, tinkering with biological code could draw a host of malicious coders. Rather than programming in 0s and 1s, future virus writers might use messenger RNA, transcription controls and segments of DNA as code. Like digital viruses, programmable pathogens would evolve through malicious modification and specialised vaccines might be necessary.

Moreover, just as the communications speed of the Internet and indirect connections to poorly secured systems lead to the rapid propagation of worms, the increasing accessibility by aircraft to parts of the world with limited medical care could lead to faster spread of viruses, both natural and man-made, said Jimmy Kuo, a research fellow for antivirus firm McAfee.

"Physical viruses have been spreading for eons through contact," he said. "Over the past century, we have increased the level of contact and that has helped viruses spread."

Until now, custom biological viruses have been the realm of science fiction. In his book Blood Music for example, author Greg Bear depicted a modified virus that accidentally spread throughout the world, changing the ecosystem. Other authors have tackled the theme of viruses that have been modified to target a single gender or race.

Just like digital viruses that target certain vulnerabilities, operating systems, or even users - the current crop of Trojan horse programs targeting bank customers are a good example - biological viruses could be made to focus on a single genetic pattern.

The potential for such specificity to become reality has worried some experts in the bioweapons field. The technology that will allow rogue scientists to target specific DNA sequences in the human genome is rapidly being developed, the British Medical Association said in a paper published in October 2004.

"While it can be hoped that ethnically specific weapons will never become a reality, it would be foolish to imagine that they are an impossibility or that incredibly precise targeting might not become possible," Malcolm Dando, Professor at the University of Bradford and a co-author of the 2004 BMA report, stated in an earlier version of the report.

The current solution is to limit access to the materials and knowledge to modify viruses. With the specialised knowledge needed to research such complex fields comes a solid understanding of the risks, said McAfee's Kuo. This coupled with restricted access to the necessary equipment and materials could reduce the threat greatly.

Princeton's Weiss agreed.

"There has been some talk in the community about limiting some of the precursors to DNA synthesis," he said. "Right now, if you are a bioterrorist, it's far easier to take something that people already know is toxic and work with that.

Yet other experts believe that controlling genetic programming and bioweapon technology will be significantly more difficult than other non-proliferation efforts, such as attempts to control the spread of nuclear and chemical weapons.

"Any biological nonproliferation regime will necessarily be less robust than its nuclear counterpart, because much of the relevant material, technology and knowledge is already far more widely distributed and will become more so in the coming decades," Christopher Chyba, Co-Director of Stanford University's Center for International Security and Cooperation, wrote in a 2002 paper on biological security.

In the article, Chyba pointed to the failure to contain most Internet threats as a picture of what is to come, stating that biological security is second only to cybersecurity in the difficulty the field poses for standard nonproliferation measures. He declined to comment for this article.